Valve bag

ABSTRACT

A valve sack for bulk material such as cement, gypsum, pellets, animal feed, or similar having a stand-up base, preferably a cross-base or a block base, and having a valve base that is disposed opposite the stand-up base and into which a valve hose is worked that forms a valve for filling the valve sack in the region of a first corner fold of the base fold, characterized in that the valve hose is formed from a thermal material and from a material different therefrom, with both materials being weldable or sealable with one another to close the valve.

The invention relates to a valve sack for bulk material such as cement, gypsum, pellets, animal feed, or similar having a stand-up base and a valve base disposed opposite the stand-up base. The stand-up base and/or the valve base is/are preferably formed in the manner of a cross-base or block-base fold. A valve tube is worked into the valve base and forms a valve for filling the valve sack in the region of a first corner fold of the base fold.

Such valve sacks, mostly produced from paper, are generally known and are in particular used for the packaging and distribution of fine-grain bulk material such as cement, gypsum, pellets, animal feed, or similar. The standard sizes in this respect are 5 kilos, 10 kilos and 25 kilos.

The valve base comprises a valve for placing the valve sack onto the filling spout of a filling system. The valve can be closed after the filling procedure such as with a hose-like thermal valve whose inner side is coated with a hot-melting material to weld the valve by the action of heat. Alternatively, sealable materials can be used for an inner side lining and closing of the valve hose.

A slip of paper is as a rule placed around the thermal material as a carrier material to improve the stability of the valve hose, in particular to be able to place it onto a filling spout of a filling system. Both materials here are formed so wide they both respectively overlap and consequently form two valve hoses disposed in one another on the folding closed of the side flaps.

An already known valve design is shown by way of example in FIGS. 1 a and b. A carrier material 2 is here adhesively bonded as a slip of paper into the open valve base 3 and subsequently a thermal material 6 is applied to the carrier material 2 in the open base 3. Both materials are designed so wide that they respectively overlap after the folding closed of the side flaps 4, 4′ in accordance with the arrows a and b and form the valve hose 7 with two hose layers disposed in one another.

If the valve hose 7 is welded after the filling procedure at the filling system, the lower part X of the thermal material 6 areally melts with the upper part Y of the thermal material 6. The carrier material 2 only has the function of a support. A disadvantage of this design is the high material effort that is required for the valve formation. This not only causes high production costs, but is also disadvantageous in an ecological aspect.

The object of the present invention is to provide a valve sack having an improved valve that can in particular be manufactured with a smaller material effort and/or less expensively and/or more environmentally friendly.

This object is achieved by a valve sack having the features of claim 1. Advantageous embodiments of the valve sack are the subject of the dependent claims.

Starting from the valve sack forming the category, provision is made in accordance with the invention to form the valve hose from a thermal material and from a material differing therefrom, with the thermal material being able to be welded or sealed with the material differing therefrom for sealing the valve. Unlike in the prior art, two layers of the thermal material are no longer welded or sealed together to bring about a valve closure, but the thermal material is rather welded or sealed with a different material. The required amount of thermal material can be reduced by this procedure. Not only production costs can thus be saved, but the valve sack is also more environmentally friendly.

Any material that can be welded or sealed with a suitably selected different material can act as the thermal material. The thermal material can preferably be a plastic material, e.g. polyethylene (PE) or also a plastic coating.

In accordance with a preferred embodiment variant, the different material is a carrier material, in particular paper. The thermal material is applied to this carrier material in a suitable manner. The application of the thermal material is selected here, however, such that it neither overlaps nor forms a closed valve hose from thermal material on the folding closed of the side flaps of the base. The valve hose consequently comprises one or more cut-outs of the thermal material along its hose periphery. The resulting hose is thus formed from the thermal material and the carrier material, with the latter closing the cut-outs of the thermal material to complete the hose. On the closing of the valve, the thermal material is weldable or sealable with the different material or carrier material. On the welding or sealing of the valve, the valve hose is compressed so that oppositely disposed inner sides of the valve hose come into contact with one another and are welded or sealed. The thermal material and the cut-outs are advantageously distributed over the inner periphery of the valve hose such that at least one strip that runs over the entire width of the valve and along whose total length thermal material is located is produced in the contact region. A tight weld or seal is thereby made possible.

The application of the thermal material to the carrier material can take place, for example, such that it is applied to the carrier material with a still open valve base approximately symmetrically or centrally with respect to the fold lines of the side flaps of the valve base and/or approximately symmetrically or centrally with respect to the longitudinal axis of the valve base and/or centrally to the surface of the carrier material facing the sack interior. The width of the thermal material, e.g. the extent of the thermal material transversely to the valve axis, is selected here such that the end sides of the thermal material neither overlap nor close to form a hose on the folding closed. The peripheral valve region that thereby remains free of thermal material is closed by the carrier material. On the compressing and closing of the valve, the thermal material is thus welded or sealed with the carrier material disposed in the oppositely disposed cut-out.

Alternatively to this, the thermal material can also be applied to the carrier material in the open valve base at the marginal side in two or more parts, in particular in the part of the carrier material that is in the region of the side flaps of the valve base, that overlaps on the folding over of the side flaps and forms the hose, and forms its semi-periphery remote from the sack body. The carrier material area facing the sack body in this case remains free of thermal material so that there is here also a valve closure by welding or sealing the thermal material with the carrier material, with thermal material being located along a strip over the entire center of the compressed valve. The thermal material is in this case preferably terminated flush with the side edges of the carrier material.

Instead of adhesively bonding the thermal material to the carrier material, the carrier material can also be provided with a corresponding weldable/sealable coating. The carrier material can be paper or any other suitable material that can be welded/sealed with the thermal material.

Alternatively to this, the use of a separate carrier material for the valve design is not absolutely necessary. The thermal material can, for example, be applied directly to the side flaps and/or corner folds of the valve base, either by adhesive bonding of a thermal material or by a suitable coating of the corresponding base surface. The forming of the valve hose is achieved in an advantageous manner after the folding closed of the side flaps by applying a top sheet to complete the valve hose. On the closing of the valve, the thermal material is welded or sealed with the top sheet in this embodiment.

A top sheet can also be applied, in particularly adhesively bonded, to the folded-closed valve base in the previously described embodiments having a separate carrier material. In the case in which the top sheet is not required to complete the valve, it can also be designed as shortened and can preferably only project up to the outer edge of the corner fold provided with the valve. The top sheet otherwise preferably projects up to the outer valve inlet edge.

Further advantages and properties of the invention will be explained in more detail in the following with reference to embodiments shown in the Figures. There are shown:

FIGS. 1a, 1b : a valve sack in accordance with the prior art;

FIGS. 2a, 2b : schematic views of a valve sack in accordance with the invention;

FIGS. 3a, 3b : representations of the valve sack in accordance with the invention with open and closed valve bases in accordance with a first embodiment;

FIGS. 4a, 4b : representations of an embodiment modified with respect to FIGS. 3a , 3 b;

FIGS. 5a, 5b representations of the valve sack in accordance with the invention with open and closed valve bases in accordance with a second embodiment;

FIGS. 6a, 6b : representations of the valve sack in accordance with the invention with open and closed valve bases in accordance with a third embodiment; and

FIG. 7: a further embodiment of the valve sack in accordance with the invention with a valve base folded closed.

FIGS. 2a and 2b show the fundamental design of a valve sack 10 in accordance with the invention that has a stand-up base 20 and a valve base 30, with the valve 50 for filling the valve sack being accommodated in the valve base 30. Apart from the valve 50 in accordance with the invention, the sack shown in FIGS. 2 a/b substantially corresponds to the solution known in the prior art. Both the stand-up base 20 and the valve base 30 are folded onto the front side 12 of the sack 10 in FIG. 2. The rear side of the sack which lies beneath the front side 12 cannot be recognized. A hose valve 50 in accordance with the invention is inserted into the valve base 30, and indeed in the region of the first corner fold 32 of the base fold. The hose valve 50 of the sack 10 can be placed onto the filling spout of a filling system and after the filling the hose valve can be welded in a dust-tight manner by the action of heat.

FIG. 2b shows the open valve base 30 of a sack 10 in accordance with the invention in a cross-base fold, with neither a valve hose nor a valve slip of paper nor a thermal material being inserted. The cross-base fold forms the two corner folds 32 and 33 as well as the side flaps 38 and 39 that are folded closed about the side fold lines 35 and 36 to close the base.

FIGS. 3a, 3b show a first specific embodiment of the valve 50 in accordance with the invention. To illustrate the valve design, the valve base 30 is not folded closed in FIG. 3a , but is rather shown open—as in FIG. 2b . A carrier material 52, a slip of paper in the embodiment, is adhesively bonded in the open base 30, on the left corner fold 32. The sealable or weldable thermal material 54, in this case a PE slip 54, is subsequently likewise adhesively bonded in the open base 30 to the carrier material 52 centrally or symmetrically to the center axis 37 of the base 30. The PE slip 54 is of a much narrower design in relation to the prior art, i.e. is shorter in the transverse direction toward the valve axis, and only a small portion (preferably 0.5 to 1 cm) projects over the two side fold lines 35, 36 into the side flaps 38, 39.

In the example shown, the PE slip 54 has to be at least as wide as the valve base 30 between the two side fold lines 35, 36. If, however, the valve 50 is narrower than the spacing between the side fold lines 35, 36 of the valve base 30, the PE slip 54 can be narrower than the valve base 30, but must be at least as wide as the valve 50 to achieve a complete weld along the contact line of the valve pressed closed.

The valve base 30 and also the valve, i.e. the valve hose 50, are formed by folding closed the side flaps 38, 39 in accordance with the arrows a and b. The top sheet 40 that extends from the valve inlet edge up to the rear corner fold 33 is adhesively bonded to the folded closed side flaps 38, 39. The valve hose 50 is completed by the carrier material 52. The PE slip 54 can no longer overlap due to the narrower design and can thus also not form any second hose. If the valve or the valve hose 50 is welded after the filling of the valve sack 10 at the filling system, the welding does not take place, as known from the prior art, on the basis of a single material (thermal material 2 in FIGS. 1a, b ), but rather on the basis of two different materials. It can be recognized in FIG. 3b that on the welding of the valve 50, the thermal material 54 at the bottom, here marked as region X′, is welded to the region of the carrier material 52 disposed thereabove, marked by the reference symbol Y′. The welding of two different materials brings about a high savings potential since less PE or thermal material 54 is required for the formation of a sufficiently tightly closing valve 50. This has a high cost advantage and simultaneously makes the valve sack more environmentally friendly.

A slightly modified version of the embodiment in accordance with FIGS. 3a, 3b is shown in FIGS. 4a, 4b . No PE slip 54 is here adhesively bonded to the carrier material 52, but the carrier material 52 is rather provided with a coating 56 instead. The positioning of the coating 56 is, however, identical to the positioning of the slip 54 in FIGS. 3a, 3b so that the effect achieved is identical to the embodiment of FIGS. 3a, 3b . The coating 56 is welded or sealed with the carrier material 52 to close the valve 50.

A further embodiment of the valve sack in accordance with the invention is shown in FIGS. 5a, 5b . The PE slip 54 is here not adhesively bonded to the carrier material 52 in one piece in the center of the valve base 30, but rather instead split into two separate regions 54, 55 that each terminate flush with a side edge of the carrier material 52. In this variant, the PE material 54, 55 is not at the bottom on the folding closed of the valve sack as shown in FIG. 3b , but rather at the top in the valve hose 50 instead. In this embodiment, however, the upwardly disposed PE material 54, 55 is also adhesively bonded to the carrier material 52 at the bottom in the valve hose. Instead of the adhesively bonded PE material, a coating could also be used here analog to FIGS. 4a, 4b . The top sheet 40 that extends from the valve inlet edge up to the rear corner fold 33 is also adhesively bonded to the folded closed side flaps 38, 39 here.

A further embodiment of the invention is shown in FIGS. 6a, 6b . In this embodiment, unlike in the above variants, the carrier material 54 is fully dispensed with and the PE slip 54 is instead directly adhesively bonded approximately centrally in the open base 30, in particular to the corner fold 33. In this case, the top sheet 40 that is adhesively bonded to the already folded closed side flaps 38, 39 serves as a replacement for the carrier material 54. The valve hose 50 is thus completely closed by the top sheet 40, with the thermal material 54 at the bottom being welded or sealed with the top sheet 40 on the closing of the valve 50. The top sheet 40 also extends from the valve inlet edge up to the rear corner fold 33 here.

The top sheet 40 is always designed up to the valve inlet edge in all the above embodiments. However, in the embodiment of FIGS. 6a, 6b , this only serves to weld the valve 50 or the thermal material 54. In the embodiment variants of FIGS. 3a to 5b , this can also be designed as shorter for a further material saving, as shown in FIG. 7. The top sheet 41 here only extends up to the ends 31, 31′ of the side flaps 38, 39.

The described embodiments use a PE material as the thermal material; however, other weldable or sealable materials are equally conceivable. The carrier material or the top sheet also does not necessarily have to be of paper, but can alternatively be produced from a different material. 

1. A valve sack (10) for bulk material such as cement, gypsum, pellets, animal feed, or similar having a stand-up base (20), preferably a cross-base or a block base, and having a valve base (30) that is disposed opposite the stand-up base (20) and into which a valve hose (50) is worked that forms a valve (50) for filling the valve sack (10) in the region of a first corner fold (32) of the base fold, wherein the valve hose (50) is formed from a thermal material (54, 55, 56) and a material (52, 40, 41) different therefrom, with both materials (40, 41, 52, 54, 55, 56) being weldable or sealable with one another to close the valve (20).
 2. A valve sack (10) in accordance with claim 1, wherein the different material is a carrier material (52) on which a thermal material (54, 55, 56) is applied, with one or more cut-outs of the thermal material (54, 55, 56) being provided over the hose periphery of the formed valve (50).
 3. A valve sack (10) in accordance with claim 2, wherein the thermal material (54, 56) is applied to the carrier material (52) centrally to the center axis (37) of the valve base (30), with the applied thermal material (54, 56) neither overlapping nor closing to form a hose with a folded closed valve base (30).
 4. A valve sack (10) in accordance with claim 2, wherein the thermal material (54, 55) is applied to the carrier material (52) in two or more separate regions over the valve periphery, with the thermal material regions (54, 55) preferably terminating flush with at least one side edge of the carrier material (52).
 5. A valve sack (10) in accordance with claim 2, wherein the thermal material (54, 55) is adhesively bonded to the carrier material (52) or is formed by a coating (56) of the carrier material (52).
 6. A valve sack (10) in accordance with claim 1, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 7. A valve sack in accordance with claim 1, wherein the different material is a top sheet (40, 41) that is applied to the side flaps (38, 39) after their folding closed.
 8. A valve sack in accordance with claim 7, wherein the top sheet (40, 41) extends up to the outer valve inlet edge or up to the ends (27, 27′) of the side flaps 38,
 39. 9. A valve sack (10) in accordance with claim 4, wherein the thermal material (54, 55) is adhesively bonded to the carrier material (52) or is formed by a coating (56) of the carrier material (52).
 10. A valve sack (10) in accordance with claim 3, wherein the thermal material (54, 55) is adhesively bonded to the carrier material (52) or is formed by a coating (56) of the carrier material (52).
 11. A valve sack (10) in accordance with claim 10, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 12. A valve sack (10) in accordance with claim 9, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 13. A valve sack (10) in accordance with claim 5, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 14. A valve sack (10) in accordance with claim 4, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 15. A valve sack (10) in accordance with claim 3, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 16. A valve sack (10) in accordance with claim 2, wherein the thermal material (54, 55, 56) is polyethylene and the different material (52, 40, 41) is paper.
 17. A valve sack in accordance with claim 11, wherein the different material is a top sheet (40, 41) that is applied to the side flaps (38, 39) after their folding closed.
 18. A valve sack in accordance with claim 10, wherein the different material is a top sheet (40, 41) that is applied to the side flaps (38, 39) after their folding closed.
 19. A valve sack in accordance with claim 9, wherein the different material is a top sheet (40, 41) that is applied to the side flaps (38, 39) after their folding closed.
 20. A valve sack in accordance with claim 13, wherein the different material is a top sheet (40, 41) that is applied to the side flaps (38, 39) after their folding closed. 